Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Cloning protocol, Sally Subcloner wants to clone a fragment into pUC19 (Map...

Sally Subcloner wants to clone a fragment into pUC19 (Map above - From New England Biolabs). Her fragment was a protein coding gene of 2.7 kb, and had Xho I sites on either end (a

Define obligatory nitrogen losses, Define Obligatory Nitrogen losses? T...

Define Obligatory Nitrogen losses? The Committee estimated the total obligatory nitrogen losses through faeces, urine, skin and other miscellaneous routes in adult men as 2.0 m

An a=t mispairing leads to an a=c substitution, An A=T mispairing leads to ...

An A=T mispairing leads to an A=C substitution. The other DNA helix will contain a(n) __ pair. a. A=C b. A=T c. G=C d. B=Q e. T=T Can you also explain it please so if I'm ask

Explain the role of calcium ions and tropnin, Explain the role of calcium i...

Explain the role of calcium ions, troponin and F-Actin during contraction in striated muscles of humans?

How the study of fossils strengthen the theory of evolution, How does the s...

How does the study of fossils strengthen the theory of evolution? The study of fossils reveals ancient and extinct species having many same structures to others of the present

ZOLOGY, The destruction of the ozone layer may be responsible for an increa...

The destruction of the ozone layer may be responsible for an increase in

Explain about the transcellular route - calcium, Explain about the Transcel...

Explain about the Transcellular Route - Calcium? Transcellular Route: It operates primarily in the duodenum and proximal jejunum. It is stimulated when Ca ingestion is lower re

Several types of steam sterilizer, The several types of steam sterilizers t...

The several types of steam sterilizers that are in use. 1. Lab Autoclave 2. Hospital dressing sterilizer 3. Bowl & instrument sterilizer 4. Rapid cooling sterilizer

Explain the process of nuclear reorganization, Process of nuclear reorganiz...

Process of nuclear reorganization in protozoa in which nucleus divides, each half undergoes a maturation, and two persisting functional nuclei reunite is termed as: a) Autogamy

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd